fixes browser/runtime_test, and a few extension member fixes

test/browser/index.html

Index: test/browser/index.html
diff --git a/test/browser/index.html b/test/browser/index.html
index b0a9a23749722526d242f429802ac273729d7967..92b69f74ce46a61f94b6d8d1e94b51da261d3ac3 100644
--- a/test/browser/index.html
+++ b/test/browser/index.html
@@ -28,7 +28,9 @@
 <script src="../../lib/runtime/dart/typed_data.js"></script>
 <script src="../../lib/runtime/dart/_isolate_helper.js"></script>
 <script src="../../lib/runtime/dart/_js_primitives.js"></script>
-
+<script src="../../lib/runtime/dart/_interceptors.js"></script>
+<script src="../../lib/runtime/dart/convert.js"></script>
+<script src="../../lib/runtime/dart/_native_typed_data.js"></script>
 <!-- tests -->
 <div id="mocha"></div>
 <script>mocha.setup({ui: 'tdd', slow: 1000});</script>